public class Q614 {
    public static double m(int i) {
        double sum = 0;
        int sign=1;
        for (int k = 1; k <= i; k++) {
            sum += sign * 1.0 / (2 * k - 1);
            sign=-sign;
        }
        return 4 * sum;
    }
    public static void main(String[] args) {
        System.out.printf("%-5s %-10s\n", "i", "m(i)");
        System.out.println("------------------");
        for (int i = 1; i <= 901; i += 100) {
            System.out.printf("%-5d %-10.4f\n", i, m(i));
        }
    }
}